In microelectronic circuits, integrated inductors are utilized to provide functions including on-die power delivery. Air-core inductors (ACIs) are commonly being utilized, and may be built in an electronic package underneath each microprocessor core. In this manner, the conventional inductor is a separate component from the other circuitry of the microelectronic circuit.
Air-core inductors (referring to an inductor that does not depend on ferromagnetic material to provide inductance) present a difficulty in scaling with the reduction in area for microprocessors resulting as microelectronics move to finer process geometries. In particular, the quality factor of the air-core inductor is generally decreasing with each generation of microprocessor. In addition, to minimize eddy current effects, the air-core inductors generally cannot have metallization or conductors such as interconnections located near to them (i.e. above or below the inductor), and as a result the inductors require a large volume.
Integrated inductors that include magnetic materials (which may be referred to herein as magnetic material inductors) can provide an alternative to air-core inductors to mitigate the area scaling trends and help maintain good efficiency at low currents. However, the implementation of magnetic materials for micro integrated inductors introduces certain difficulties. In particular, eddy currents present a significant challenge with conductive magnetic materials, greatly reducing the quality factor for such integrated inductors.